Dragons of Sea <md Air 



While the structure of the teeth and jaws 

 indicates that none of the herbivorous dinosaurs 

 ground their food after the manner of horses 

 and cattle, the jaws of Triceratops were even 

 more strictly confined to cutting than were 

 those of other species. The lower teeth were 

 flat on the outer face and the upper teeth flat- 

 tened on the inner side, and they slipped by 

 one another much like two coarse saws, shear- 

 ing off anything that might be between. 



These dinosaurs were among the last of 

 their race, although their enemies, the carniv- 

 orous Theropoda, endured with and probably 

 preyed upon them to the end. But dinosaurs 

 ended with the Cretaceous, and after that mam- 

 mals, which had been struggling along in a 

 small way, took possession of the earth. 



A still higher type of reptilian life was 

 present in the shape of pterodactyls, or flying 

 reptiles, and in view of the apparent scarcity 

 of birds these may well have laid claim to the 

 empire of the air.* They are placed first in 



* The writer is well aware that this phrase has been employed 

 by M. Mouillard for the title of a book, but does not on that 

 account wish to forego all right to use the term. 



209 



